Diaphragm pump



H. F. HADLEY 2,455,480

DIAPHRAGM PUMP Filed Nov. 6. 1944 1 13 J4 M ATToRN Patented Dec. '7,1948 DIAPHBAGM PUMP Harold F. Hadley, Defiance, Ohio,asslgnor to DapcoProducts, Inc., a corporation of Ohio Application November s, 1944,serial No. 562,163

4 claims. (ci. 25a-17o) This invention relates to fluid pumps and moreparticularly to pumps or compressors of the diaphragm type especiallyadapted for compressing gases. v

Pumps and compressors of the diaphragm type have been constructed forcomparatively low, pressure and small volume operation especially forcompressing air and other gases, and have proven fairly satisfactory forthis character of work. When attempts have been made to use a compressorof the usual diaphragm type for high pressures or large volumeoperations, diaphragm rupture and other attendant diiculties have beenencountered which in the past have resulted infailures.

The present invention has for a principal ob- .lect the provision of afluid pump or compressor of the diaphragm type `capable oi operation athigh pressures and of compressing comparatively large volumes of gas forlong periods of time without diaphragm failure.

Another object of the invention is the provision of a diaphragmcompressor especially adapted for compressing gases to high pressures inconjunction with a valve arrangement which permits gas to be compresseduncontaminated with oil or other lubricant.

Another object is the provision of a unitary '1 diaphragm constructionwherein a metallic ilexible element is bonded to a metal member in sucha manner that th'e diaphragm is capable of operation over'long periodsof time at high pressures without failure.

Another object is the provision of a unitary diaphragm constructionwhich may be readily replaced in a comparatively short time without theuse of special tools.

Still another object is the provision of a dia' drawing of a form of theinvention, which may be preferred, in which:

Figure 1 is a vertical sectional view illustrating a compressorembodying a form of my invention;

Figure 2 is a horizontal view taken substantially on the line 2--2 ofFigure 1; y

Figure 3 is a fragmentary vertical sectional view taken substantially ontheline 23 of Figure 1 s Figure 4 is a horizontal sectional view takensubstantially on the line 4--4 of Figure 3;4

Figure 5 is a plan view showing a portion of the diaphragm arrangementper se:

Figure 6 is a sectional view showing a portion of the diaphragmconstruction.

While I have illustrated the arrangement of my invention as particularlyadapted for use in compressing gases, such as air to comparatively highpressure, it is to be understood that my invention may be utilized forpumping liquids. or as a vacuum producing means, or for any otherpur-`pose where it may be found to have yutility.

Referring to the drawingsin detail, the apparatus is inclusive of ahousing I0 formed with an opening in the front thereof normally closedby a cover Il, the latter having a screened breather opening I2 tofacilitate equalization of air pressure in the housing. The housing-I0is adapted to be secured to the frame structure or end-plate I3 of amotor I4 adapted to actuate the compressor. The upper portion of thecompressor housing I0 is enlarged or ared outwardly as at IG theenlarged portion having-a peripheral flange I1.

The diaphragm construction of my invention is inclusive of an annulus orring preferably formed of metal, as for example', brass to which isbonded or vulcanized a iiexible element or diaphragm 22 as at 23. Theiiexiblel element 22 is of annular conguration, the inner wall of whichis bonded or vulcanized to a circular member or metal disc 25. As thediaphragm construction forms an important part of the present invention.it will be hereinafter described in further detail. The member 25 isformed with a circular recess 26 adapted to receive a disc-like member21 lixedly secured to member 25 by means of screws 28.'

Integrally formed with' member 21 are shaped depending bosses 30 and 3lhaving aligned openings adapted to accommodate a journal pin 32 retainedin place by screws 33. A connecting rod 35 has its upper end bored toaccommodate a needle bearing 31 which surrounds the journal pin 32.Positioned between boss 3| and the connecting rod is a thrust bearing 38preferably of the self-lubricating type. Boss 30 and the upper end ofthe connecting rod 35 are formed with laterally extending projectionsdesignated 40 and 4I respectively. Positioned between each set oiprojections are resilient elements I2 as shown in Figure these elementsbeing preferably blocks or rubber, synthetic rubber or the like. Theresilient element 42 are subjected to initial compression for thepurpose of exerting continuous lateral pressure upon the thrust bearing35 and thus function as a vibrationdamping means for cap H6, the lattersecuring a ball bearing 41 inthe end of the connecting rod. The innerrace of the bearing 41 fits the exterior surface of a cylindrical memberB8 which is bored to nt the motol` shaft iig, the member i8 being fixedto the shaft by means of a key 55. The axis of the exterior cylindricalsurface of member 48 is eccentric with respect to the axis o'f the motorshaft I9, which eccentricity causes reciprocation of the connecting rod35, members 25 and 27, and diaphragm 22 during rotation of the motorshaft. Member 48 is formed with a projection 52 for the purpose ofcounterbalancing the "pull" of the reciprocating parts of the-compressorstructure.

Positioned above the diaphragm construction is a` valve carrying memberor plate 55. A head 56 of the compressor having heat radiating fins isformed with an annular surface 51 arranged to secure the plate 55 inposition on the housing i6, there being annular gaskets 55 interposedbetween the head 56 and plate 55 andbetween the plate 55 and member 20to effect sealed joints. The head 55 and plate 55 are secured inposition by means of screws 59 threaded into openings formed in theperipheral portion i1 of the housing I0. The plate 55 is provided with aconcentrically arranged upwardly extending wall 50 which with adepending annular wall 5l on the head 55 forms an air inlet'passage 52for the compressor chamber 53. Interposed between-the adjacent edges ofwalls 60 and 5I is a resilient gasket 54 of compressible materIaL-.asfor example, rubber or the like arranged to seal the joint between thewalls. The wall 5I is provided with an annular abutment 65 so that thehigh pressure of the compressed air or fluid will not dislodge thesealing member 63. The head 55 has a threaded opening 56 to accommodatean air lter (not shown).

The outer wall 51 of the head 55 together with the walls 6|) and 6Idenne an annular plenum chamber 68 surrounding the air inlet passage 52the wall 51 having an air outlet passage 10 arranged to accommodate atube 10' or other means for conveying the compressed air or other fluidto the place where it is used.

The valve mechanism of thev compressor is carried by the plate 55. Inthe form of the invention illustrated, the plate 55 is provided with apair of 'inlet passages or ports 1i communicating between the walledpassage 62 and the compression chamber 63, The inlet ports 1i are ofelongated configuration, and are normallyclosed by flexiblel reed-likevalves or plates 12. One end of each valve is xedly secured to the plate55 by rivets 15, the valves being arranged in opposed relation as shownin Figure 2, i. e. the free or 'movable extremities of the valvesextending in parallel but opposite directions so as to facilitate rapidpassage of air or other fluid through the passage 62 into thecompression chamber 52.

Similarly constructed valves 15 are arranged to normally close theoutlet ports 18 and are also arranged with the free or movableextremities extending in parallel and opposite directions. This valvearrangement enhances the passage of gas lfrom the compression chamber 63into the plenum chamber 85.

The diaphragm or flexible element 22 is pref' erably made of rubber,synthetic rubber of the neoprene type or the like and is so bonded tothe members 20 and 25 that continued ilexure during compressionoperations does not dislodge the bonds. The arrangement of my inventionis particularly adaptable for compressing gases to comparatively highpressures as well as having utility in pumping liquids. I have found acomparatively thick diaphragm with respect to its width must be employedin order to secure satisfactory results under high pressures withoutencountering diaphragm failure. One example of a practical constructionwhich I have employed in developing compression pressures exceeding 150lbs. per square inch is as follows: a compressor in which the outsidediameter of the flexible element 22 is seven inches, and the diam- 'eterof metal member 25 `is four and one half inches, a thickness ofapproximately three quarters of an inch for the flexible element hasbeen found to be satisfactory. I have found that the followingapproximate proportions of flexible diaphragm dimensions will givesatisfactory results. 'I'he thickness T (see Figure 6) of diaphragm orflexible element 22 should be at least equal to or greater than one halfthe width W of the element when the ratios of the diameter of member 25to the diameter of the elementare substantially in the proportion offour and one half to seven. If the width of the flexible element 22 isincreased, the' thickness should be proportionately increased.

While other proportions of width and thickness of flexible element 22may be employed without departing from the spiritof the invention, Ihave found that by utilizing the above mentioned general proportions,very little bulging or flexure of the flexible element is encounteredunder pressure. It is not suillcient to materiallyl affect thecompression stroke so that a high compression and volumetric efficiencyis maintained even; at comparatively high pressures.

In the operation of the compressor. the motor i4 is started (that shownbeing electrically operdownward stroke of the connecting rod and dia- .4

phragm structure, as viewed in Figures 1 and 3, sets up a. differentialin pressure between the compression chamber and passages 52 which causesthe inlet valves 12 and 13 to open, permitting air or other fluid toflow through the ports 1I into the compression chamber 55. Onthe upwardstroke of the diaphragm construction, the valves 12 are closed, causingthe air or fluid to be compressed in chamber 63. When the pressurewithin the chamber 53 exceeds that in the plenum chamber 58, the valves15 are opened by reason of the higher pressure in chamber 52. causingthe air or other fluid under pressure to flow through the outlet ports15l`into the annular v plenum chamber or reservoir 56. The fluiduninvention, modiiications and different arrangements may be made otherthan is herein disclosed, and the present disclosure is illustrativemerely, the invention comprehending all variations thereof.

Iclaim:

1. In combination, a compressor including a housing, a. plate in saidhousing, valved ports in said plate; a compressor head; a diaphragmconstructionin said housing and forming with said plate a' compressionchamber; said diaphragm construction including a metal ring removablysecured to said housing; a disc-like member in said housing; animperforate stretchable diaphragm of uniform thickness bonded to saidring and said disc; and mechanical means associated with said disc-likemember for positively effecting successive suction and pumping strokesof said member and stretchable diaphragm, said metal ring, diaphragm anddisc being of substantially the same thickness.

2. A removable pumping element for a compressor including a metalannulus; a metal disc arranged within said annulus and spaced therefrom;an imperforate stretchable element of rubber or the like vulcanized tosaid annulus and said disc; said element being of uniform thickness andsubstantially the thickness of said metal :annulus at the point ofjuncture therewith and of a width in cross section substantially twicethe thickness thereof.

3. In combination, a pump including a housing; a. plate in said housing;valved ports in said plate; a diaphragm construction in said housing;said diaphragm construction and said plate forming a pumping chamber;said diaphragm construction including an annulus of nonresilientmaterial removably secured to said housing; a disc-like member in saidhousing; an imperforate stretchable element of uniform thicknesspermanently bonded to said annulus and said member; and mechanicalmeansv associated with said disc-like member for eiecting successivepumping strokes of said member and stretchable element; said annulus,stretchable element and disc-like member being of substantially the samethickness.

4. A removable pumping element for a compressor including an annulus ofnon-resilient material; a disc-like member ofy non-resilient materialarranged within said annulus and spaced therefrom; an imperforatestretchable element of rubber or the .like bonded to said annulus andsaid member; said element being of uniform thickness and substantiallythe thickness of said annulus at the point of juncture therewith and ofa width incross-section substantially greater than the thicknessthereof.

HAROLD F. HADLEY.

REFERENCES CITED The following references are of record in the le ofthis patent:

